Suberoylanilide Hydroxamic Acid Restores Estrogen Reduced-cTnI Expression in Neonatal Hearts of Mice

Regulatory effect of Panax notoginseng saponins on the oxidative stress and histone acetylation induced by porcine circovirus type 2

Porcine circovirus type 2 (PCV2) exists widely in swine populations worldwide, and healthy PCV2 virus carriers have enhanced the severity of the infection, which is becoming more difficult to control. This study investigated the regulatory effect of Panax notoginseng saponins (PNS) on the oxidative stress and histone acetylation modification induced by PCV2 in vitro and in mice. In vitro, PNS significantly increased the scavenging capacities of superoxide anion radicals (O2•-) and hydroxyl radicals (•OH) and reduced the content of hydrogen peroxide (H2O2) induced by PCV2 in porcine alveolar macrophages (3D4/2). In addition, PNS decreased the protein expression level of histone H4 acetylation (Ac-H4) by increasing the activity of histone deacetylase (HDAC) in PCV2-infected 3D4/2 cells. In vivo, PNS enhanced the scavenging capacities of •OH and O2•- and reduced the content of H2O2 in the spleens of PCV2-infected mice. PNS also reduced the protein expression level of histone H3 acetylation (Ac-H3) by reducing the activity of histone acetylase (HAT) and increasing the activity of HDAC in the spleens of PCV2-infected mice. PCV2 infection activated oxidative stress and histone acetylation in vitro and in mice, but PNS ameliorated this oxidative stress. The research can provide experimental basis for exploring the antioxidant effect and the regulation of histone acetylation of PNS on PCV2-infected 3D4/2 cells and mice in vitro and in vivo, and provide new ideas for the treatment of PCV2 infection.

Histone deacetylase inhibitor MGCD0103 protects the pancreas from streptozotocin-induced oxidative stress and β-cell death

Inhibition of histone deacetylase (HDAC) suppresses inflammation of pancreatic islets and apoptosis of β-cells. However, the underlying molecular mechanism is unclear. In the present study, we demonstrate that MGCD0103 (MGCD), an HDAC inhibitor, protects the pancreas from streptozotocin (STZ)-induced oxidative stress and cell death. Sprague-Dawley rats were intraperitoneally injected with STZ (40 mg/kg) to induce type I diabetes. MGCD (10 μg/day) was infused with osmotic mini-pump for 4 weeks. Pancreatic insulin and macrophage infiltration were analyzed by immunohistochemistry. Cellular level of reactive oxygen species (ROS) was evaluated with fluorescence-activated cell sorting. Tetramethylrhodamine ethyl ester was used to analyze mitochondrial membrane potential. Activation of caspase-3 was analyzed by western blotting. Chromatin immunoprecipitation was performed to investigate the binding affinity of specificity protein 1 (SP1) on the promoters of target genes. mRNA expression was analyzed by quantitative real-time polymerase chain reaction. As a result, we found that MGCD infusion ameliorated STZ-induced hyperglycemia, islet deformation, decreased insulin level, and macrophage infiltration. STZ injection promoted the production of ROS, which induced caspase activity and β-cell death. 4-Hydroxy-2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPOL), a mimetic of superoxide dismutase (SOD), reduced STZ-induced caspase activity and β-cell death. MGCD treatment increased SOD expression and histone acetylation level on promoters. Infusion of MGCD promoted acetylation of SP1 and its enrichment on SOD promoters. Thus, MGCD protects pancreatic β-cells from STZ-induced oxidative stress and cell death through the induction of antioxidant enzymes such as SODs.